Few questions about Hostname and emails

I'm currently brand new to ISPConfig and I'm very happy with it but i have some questions.

1. Is there any step-by-step guide how to configure one example domain + mail + sub domain + ftp ? I found one link here at forum but its not working that ftp any more...

2. when i creating domain (i have DNS on another server ) there is a Host name and Domain option... Domain is ok ( something line bash.sk ) but what i should put into Host name ? i have there www now and everything is working fine...

3. Here is bigger issue with mails... i created my domain, bancodata.eu, than under "User & Email" created new user so i can have ftp with my page..

i put email like [email protected], username: web2_info, and setup password... now ftp is working fine, page also but not an email...

I installed squirell mail to ISPConfig and i can log in by using whole email address " [email protected]" and pass for user web2_info, and also sen email from there, but i do not receiving any emails... also when i send mail from squirell mail it will come with From:[email protected] where thats come from ??

I also cant log in by any mail client, the same username and password which is working for squirell its not working for email clients...